Components

The LM7805 is a very popular voltage regulator. Curious about how it works? In this AddOhms Tutorial, we look at what is a Linear Voltage Regulator and how to use them in your circuits. Linear Voltage Regulators Show Notes Related Datasheets LM7805 [Fairchild] NCP1117 [On Semiconductor] PIR Sensor [Adafruit] Interesting Links Written Tutorial on Regulators [ Baldengineer.com] TO-220 Information [Wikipedia] TO-220 Heatsink [Adafruit] Choosing the right LDO [All About Circuits]

There is nothing more frustrating than a push button that seems to work at random. The good news is the fix is pretty simple: a resistor. It may not seem obvious when you first start working with electronics but a “floating pin” doesn’t have a defined “high” or “low” level. Remember from the Analog and Digital video, that Digital Electronics has defined voltage levels. Well, when you don’t connect anything to the I/O pin of your microcontroller, the voltage level is undefined!

https://youtu.be/EQtwsWJuUPs Understanding voltage dividers means understanding Ohm’s Law. A common use for a voltage divider in most projects is to monitor a battery. Say you are powering your circuit with a 9V or 12V battery. Microcontroller boards don’t do well with those voltages. In a future video, we’ll come back and look at more circuits that can use voltage dividers. Episode Notes Correction: There is a mistake around 3:00. I say “91 millivolts” and I should have said “910 millivolts!”

https://youtu.be/GrvvkYTW_0k Following up from Episode #10 on BJTs, this episode is focused on introducing MOSFETs. It is the longest video we’ve done yet, coming in just over 7 and a half minutes. There is a basic overview of how MOSFETs work, compared to a BJT. And something that is really important to consider: how hot is it going to get? So we go through how to calculate power dissipation and if you need a heat sink.

https://youtu.be/sRVvUkK0U80 The two most popular kinds of transistors you might use for a project are either BJTs or MOSFETs. With so many options, it was tough to pick just a few. We covered the 2n3904 in this video. What BJTs are your favorites and why? Leave a comment below. Transistors are electronic switches that are used to control things that would kill an Arduino, Raspberry Pi, or Beaglebone. There are two major types known as a BJT and MOSFET. This is part 1 of a two part series, which looks at BJTs first.